Cable Ship

a ship to lay submarine communications cables and power lines; also used to raise such cables from the bottom and to repair them. The first cable ship was the small English steam tugboat Goliath, which on Aug. 28, 1850, was used to lay the first submarine telegraph cable across the Strait of Dover. The largest cable ship of the 19th century was the English steamship Great Eastern, with a displacement of 32, 000 tons, designed by the English engineer I. Brunei. The Great Eastern was used in 1865-74 to lay the first series of transatlantic telegraph cables. During the 1960’s the world fleet of cable ships consisted of more than 30 vessels, among them the British ships Monarch (displacement, 12, 000 tons; built in 1946) and Alert (8, 000 tons; 1961), the French ship Marcel Bayard (7, 000 tons; 1961), the Soviet ships Ingul and Iana (each 6, 900 tons; 1963), and the American ship Long Lines (17, 000 tons; 1962).

The holds of a cable ship, which are cylindrical containers, are called tanks. As many as several thousand kilometers of submarine communications cable are coiled and placed in the tanks. During the cable-laying operation, electric signal repeaters are installed in the cable in special rooms on the deck of the ship, called hangars. The ends of each manufactured length of cable (10-50 km long) are carried onto the deck and are connected to the appropriate repeater. Thus, the assembled length can be either the total length of the main line or the part of the length that can be stored in the cable ship before the laying of the cable is begun. Electrically driven cable machines are used to lay the cable or to raise it for repairs; one such machine is located at the stern and two at the bow (port and starboard). A cable equipped with repeaters is laid from the stern; cables without repeaters are laid from the bow. Cables are also raised from the bow of the cable ship. A cable winch develops a force up to several hundred kilonewtons (tens of tons-force); it has tensioning equipment incorporating pulleys 2-3 m in diameter or of the caterpillar type. The latter type is preferred for laying a cable equipped with repeaters in rigid cylindrical housings. A cantilever (outrigger) protrudes from the bow of the ship; it is equipped with pulleys for the cable being laid and for the carrying cable used in raising. Cable-laying at depths of 5, 000-6, 000 m is conducted at speeds up to 8 knots (15 km/hr); when repeaters are passing through a cable machine the speed of laying is reduced to 1-2 knots. Cable ships are equipped with apparatus that provides continuous control of the characteristics of the cable being laid or repaired and of the condition of the repeaters. Cable ships are also equipped with apparatus for maintaining ship-to-shore communications through the cable being laid; equipment used in searching for the cable or in raising the cable, including grappling devices (grapnels); buoys for temporary marking of a damaged cable section; floats used in carrying a cable to the shore; and equipment for splicing cable ends.

Ordinary freighters and tugboats are used to lay cables in rivers, lakes, canals, coastal waters, and harbors. Such ships are temporarily equipped with winches used in laying or raising the cable and with large-diameter pulleys, which are located at the stern (for laying cable) or at the bow (for raising cable).